• Please review our updated Terms and Rules here

Project: Motherboard for Intel Wildcard 88 module

sergey

sergey

Veteran Member
Joined
Jul 15, 2010
Messages
879
Location
Silicon Forest, Oregon, USA
I've bought a few Wildcard 88 cards a couple years ago in eBay. So I was planning to make a system around them, which got delayed due my other responsibilities and projects... Anyway, I found some time last two weekend to work on this. The preliminary description of the design is here: http://www.malinov.com/Home/sergeys-projects/wildcard-88-motherboard

The Wildcard 88 is an interesting card. It is basically a PC on a stick - a 2"x4" module that implements an XT motherboard functionality (less DRAM).
My motherboard design adds some ISA slots, AT2XT converter, DRAM interface, and few other components.

I'd like to hear any suggestions for this project. Also I think several others on this forum might have Wildcard 88 modules... If you do, please let me know if you're interested in this motherboard (so I'll order the appropriate number of PCBs).

Thanks,
Sergey

Wildcard 88 - Front.jpg
Wildcard 88 - Back.jpg
 
You never believe it but last Saturday i was going to my pile of vintage computer parts and found my Wildcard module i save from the trash at work a year ago.
So i was searching if anyone has made a motherboard for this module and the next day i found sergey's project about the exact same thing :)

For suggestions i would have made everything using SMD components but that is not something everyone can easily assemble.
And another thing i was thinking about was to use a couple of dc to dc converters so the hole board could be powered from an old power brick.
 
You never believe it but last Saturday i was going to my pile of vintage computer parts and found my Wildcard module i saved from the trash at work a year ago.
So i was searching if anyone has made a motherboard for this module and the next day i found sergey's project about the exact same thing :)

As for suggestions i would have made everything using SMD components but that is not something everyone can easily assemble.
And another thing i was thinking about was to use a couple of dc to dc converters so the hole board could be powered from an old power brick.
 

Attachments

  • Front.jpg
    Front.jpg
    75.3 KB · Views: 2
  • Back.jpg
    Back.jpg
    67.1 KB · Views: 2
  • WILDCARD7354-1001REV2.52.05.zip
    8.4 KB · Views: 3

Attachments

  • Socket.jpg
    Socket.jpg
    87.5 KB · Views: 2
pietja said:
Maybe a nice addition is a real-time clock like on the Xi 8088 board, its the only thing missing for making a complete PC if you add the cards you designed for the Xi 8088 board.

I also scavenged some of those special 68pin simm headers from an old broken Apple PowerMac video card.
http://www.vgamuseum.info/index.php/component/content/article/674-apple-1mb-hpv-pds-video-card
Click to expand...

Oops... too late, already ordered PCBs without RTC :)
My thinking was that RTC is not an essential part... also I was trying to save PCB space.

Regarding sockets - I was looking for these 68-pin SIMM sockets, but I haven't find any. So my current plan is to cut a 72-pin SIMM socket in two places and remove two pins on each side.
 
So the next project is an XT-RTC ;)

It could be a very basic card wit just a DS12885/DS12887 (AT class) or MM58167/UM82C8167 (used on the old XT RTC cards) and battery on it.
And just like the old XT RTC cards we have a little utility in the AUTOEXEC.BAT to set the time at start-up or have an extension ROM to do that.

Like the XT-IDE and XT-FDC it could be a useful card for the many IBM PC and XT users out there because i haven't been able to find those RTC cards on eBay and the RTC chips are still available.
 
pietja said:
So the next project is an XT-RTC ;)

It could be a very basic card wit just a DS12885/DS12887 (AT class) or MM58167/UM82C8167 (used on the old XT RTC cards) and battery on it.
And just like the old XT RTC cards we have a little utility in the AUTOEXEC.BAT to set the time at start-up or have an extension ROM to do that.

Like the XT-IDE and XT-FDC it could be a useful card for the many IBM PC and XT users out there because i haven't been able to find those RTC cards on eBay and the RTC chips are still available.
Click to expand...

I was toying with the idea of a multifunction ISA card... something like:
- SRAM - to extend IBM PC/XT memory to 640K, implement UMBs, and perhaps EMS functionality.
- EEPROM/Flash ROM - for BIOS extensions
- Mass storage (CF, or perhaps SD card based)
- Floppy disk controller
- UART (or a couple of them, e.g. using 16552 chip)
- Jumper-less configuration... This one can be implemented using a microcontroller.

RTC could be a nice addition to this board...

Thanks,
Sergey
 
I received the PCBs and built the motherboard. I am happy to report that the motherboard is working (I had a small trouble due to faulty SIMM module). I updated the project page with all the latest design information.

Front view:
Motherboard - Front.jpg

Back view:
Motherboard - Back.jpg

Booting MS-DOS:
Boot.jpg

pietja said:
You never believe it but last Saturday i was going to my pile of vintage computer parts and found my Wildcard module i saved from the trash at work a year ago.
So i was searching if anyone has made a motherboard for this module and the next day i found sergey's project about the exact same thing :)
Click to expand...

pietja: I have an extra PCB in case you want to build a motherboard for you Wildcard 88. PM me...

I also programmed the BIOS that you've attached, and it works nicely on my Wildcard 88 boards. The interesting thing is that my boards have 27C128 (16 KiB) EPROMs [my boards are apparently from The Leading Edge Model D systems], and your BIOS is 32 KiB.
 
sergey i don't know why the bios in my Wildcard is 32k but when i opened it in an hex editor it looked like there was a lot unused space.

Also did your Wildcard worked without problems with the ISA Super VGA card you designed ?
For me i'm still waiting on some parts to finish my board.
 
Last edited:
Hi sergey caught your site re wildcard 88. What sort of cost for motherboard x 1? Excellent documentation btw!
 
pietja said:
sergey i don't know why the bios in my Wildcard is 32k but when i opened it in an hex editor it looked like there was a lot unused space.
Click to expand...

Possibly in late 80's the 27C256 was just as cheap as 27C128, or system manufacturer added something to the BIOS, and its size was just a tad more than 16 KiB. Documentation mentions that Wildcard supports ROMs up to 32 KiB specifically so that OEMs can put their own code in there (I guess might be useful for embedded systems).

pietja said:
Also did your Wildcard worked without problems with the ISA Super VGA card you designed ?
For me i'm still waiting on some parts to finish my board.
Click to expand...

Yes it worked with my ISA Super VGA card. The only thing is that I had to install a J1 (VID0) and J2 (VID1) jumpers so that BIOS won't try to initialize display card (and will let VGA BIOS do that). The VID0 is available on the motherboard (JP1), but J2 is not. So it needs to be installed on the Wildcard 88 itself.
 
bobba84 said:
Sergey,do you have any of the wildcards themselves available too? If so, how much would you want for both?

Thanks!
Bobby.
Click to expand...

I sold the spare PCB I had, and unfortunately I don't have any spare Wildcard 88 boards. They appear on eBay every so often. I've seen one recently, but it was largely overpriced ($100?!). I think the fair price is $20 or less :)
 
cliffk said:
Hi sergey caught your site re wildcard 88. What sort of cost for motherboard x 1? Excellent documentation btw!
Click to expand...

I sold the spare PCB I had. The price was $50 (I ordered a set of 3 boards from OSH Park, and paid $150 for them). It is quite possible to make cheaper PCBs if ordering more, but I was not sure how many people would actually want to get a PCB.

Anyway, if you want to make/order PCB yourself, the KiCad design, the Gerber files, and a link to the OSH Park project are available on the project page.
 
I always respect and appreciate Sergey's Projects. I Built a Wildcard 88 motherboard. It works fine on VGA, but I get memory errors on MDA(HGC),CGA. I hope to solve this. Can someone give me some ideas?20230220_160714.jpg20230220_160716.jpg20230220_160718.jpg
 
Welcome to the forum @antwork !

The error shown is interesting, as it says that it was expecting ‘FF’ in hex, and instead got ‘FF’. Maybe this is a display bug?

- Alex
 
You must log in or register to reply here.
Back
Top